;o 
IOWA ACADEMY OP SCIENCE 
It may be added that Schofield^' foiind that the seeds of Zizania aquat- 
ica soon lose their vitality if exposed to the air and that they germinate 
only when kept in moist earth or mud. Mr. J. J. Thornber^'^ finds that 
with seeds flooded to a depth of 12 inches for a period of 30 days, there 
were obtained germinations as follows : Bermuda grass 42 per cent, 
Johnson grass 45 per cent, Sesbania macrocarpa 75 per cent. When 
extended to 50 days, Bermuda grass germinated 14 per cent, Johnson 
grass 23 per cent. After submergence of 21 days, radish, rutabaga, 
sugar beet and tomato seed germinated 100 per cent, cabbage and celery 
seed 75 per cent, and water melon 33 per cent. 
There may be mentioned in connection with studies of germination 
under induced conditions, the experiments of Italo GigliolT" who has 
shown that latent vitality may occur in seeds when surrounded by gases 
and liquids. The seeds of alfalfa Avhen in nitrogen dioxide for 776 
days germinated 43 per cent, sulphuretted hydrogen 976 days germi- 
nated 58 per cent; arseniuretted hydrogen 802 days germinated 87 per 
cent. The seeds were air dry and placed in bulbs. In regard to liquids 
the results are surprising, methyl alcohol 841 days, per cent of germi- 
nation 19 per cent; carbon disulphide 405 days per cent of germination 
63.2. Moist seeds kept in oxygen and in nitrogen protoxide do not 
germinate. Alcoholic solution of iodine 382 days, per cent germination 
1.5, alcoholic solution of potassium bromide 757 days 68.4. Giglioli 
re-examined the seeds of alfalfa which had been kept in the gases and 
liquids during this time; Hydrogen 16 years, none germinated; wheat 
and cynara gave the same result. With chlorine and hydrochloric acid 
gas, seeds of alfalfa 16 years, 3 months and 5 days old, 6.72 per cent 
germinated. Alcoholic solution of sulphuretted hydrogen, alfalfa 15 
years, 9 months, 15 days, 7.03 per cent germinated. These experiments 
seem to show that seeds may retain their vitality when all respiratory 
exchange is completely prevented for a long series of years. 
To test the vitality of clover seed gathered in the year 1905, the 
following experiment was conducted the seeds were treated with hot 
water, dilute sulfuric acid, concentrated sulfuric acid and, in one case, 
by scratching. 
^^The Viability of Seeds. Plant World 11:158. 
^“Latent Vitality of Seeds. Nature 52:544. Action of Gases and liquids on 
the Vitality of Seeds. 35:328. 
Gazette Chimica italiana. 9:19. 1879. 
Gior delle staz sper, ital. 8:199. 1874. 
®®This experiment was conducted by J. R. Campbell under our direction. 
